PCT patent application publication No 03/019072A discloses a prior LED lighting device. The prior LED lighting device having a plurality of light emitting units on a circuit board. Each the light emitting unit is configured to emit the light having color which is different from the color of the light emitted from the other light emitting unit. The LED lighting device comprises a plurality of the light emitting units which is cooperative with each other to produce light having a desired color temperature. In this manner, the LED lighting device is configured to produce a white light.
The prior LED lighting device comprises a first light emitting unit, a second light emitting unit, and a third light emitting unit. The first light emitting unit is composed of a blue LED chip and a YAG phosphor. The blue LED chip includes indium, gallium, and nitrogen (InGaN). The blue LED chip is configured to emit light having an emission peak wavelength of 450 to 460 nm. The YAG phosphor includes yttrium aluminum garnet. In the first light emitting unit, the blue LED chip emits the light which excites the YAG phosphor, whereby the first light emitting unit emits a white light. The first light emitting unit is adjusted to emit the light having a desired color temperature on the blackbody locus. The second light emitting unit is composed of a orange LED chip which includes AlInGaP. The second light emitting unit is configured to emit light having an emission peak wavelength of 590 nm. The third light emitting unit is composed of a blue LED chip which is configured to emit light having an emission peak wavelength of 470 to 480 nm. The second light emitting unit and the third light emitting unit are act as auxiliary light sources of the first light emitting unit. The LED lighting device comprises the first light emitting unit, the second light emitting unit, and the third light emitting unit which are combined with each other to produce the light having the desired color temperature. The LED lighting device as mentioned above is used as shadowless lights, interior lamps, and so on.